There are several reasons why the machine stop:
1,check the inner wall of combustion chamber and nozzle Whether carbon deposition .
Inspection method
Remove the machine in front of the smoke pipe and gas pipe,
To expose the combustion chamber nozzle . and use flashlight observe the interior of the nozzle ,
If deposit carbon deposition must be completely clean
2 check pressure ignition switch cover leakage or not
inspection method,
Unplug the tube nearest carburetor and medicine chest ,
Towards the ignition cover the one-way valve direction blowing . when you blowing please attention to hear he one-way valve leak or not ,The spark plug is "squeak" sound ignition.
If you hear the sound of leakage, note that the ignition cover one-way valve diaphragm deformation or cracks in the ignition cover, check after replacement. After replacement of re blowing test, if no leakage is OK
3 Check the fuel tank cover ring damage or not , if damag change a new ring.
do you understand above explain? if not i ask again